Q.3. How many 3-digit even numbers can be made using the digits
1, 2, 3, 4, 6, 7, if no digit is repeated?
3-digit even numbers can be made using the digits 1, 2, 3, 4, 6, 7, if no digit is repeated.
The unit place can be filled in 3 ways by any digits from 2,4 or 6.
The digit cannot be repeated in 3-digit numbers and the unit place is occupied with a digit(2,4 or 6).
Hundreds, tens place can be filled by remaining any 5 digits.
Therefore, there will be as many 2-digit numbers as there are permutations of 5 different digits taken 2 at a time.
Therefore, the required number of 2-digit numbers
Thus, by multiplication principle, required 3 -digit numbers is